Excellent microwave absorption properties of Fe ion-doped SnO₂/multi-walled carbon nanotube composites

In this work, Fe ion-doped SnO₂/multi-walled carbon nanotubes (MWCNTs) composites were synthesized using a hydrothermal method. X-ray diffraction, TEM, Raman and X-ray photoelectron spectroscopy, and vector network analyses were conducted to demonstrate the structure, interaction, morphology, chemical content, and electromagnetic parameters of the Fe ion-doped SnO₂/MWCNTs composites. The as-structured Fe ion-doped SnO₂/MWCNTs composites were proven to be outstanding lightweight microwave absorbers when the Fe ion doping percentage was relatively high. Fe ion doping at a molar percentage of 48.8% resulted in a maximum reflection loss (RL) of −44.5 GHz at 15.44 GHz with a layer thickness of 1.5 mm. The maximum RL ≤ −10 dB reached 4.5 GHz at the Ku band. The excellent microwave absorption of the as-prepared composites was principally due to proper attenuation and impedance matching, electric polarization, interfacial polarization, and conductive network. Such composites may have further applications in microwave absorption.